1. Field of Invention
This invention pertains generally to cellular telephones and, more particularly, to an electromagnetic shield for protecting users of cellular telephones from harmful radiation.
2. Related Art
In recent years, as the number of hand-held cellular telephones has grown, so has the concern about tumors or other damage to the brain. Although the level of electromagnetic radiation emitted by such devices is relatively low, the antenna which emits the radiation is close to the head, and there is also concern that the radiation can have a cumulative effect.
In the past, there have been some attempts to protect the users of cellular from such radiation. However, none of those approaches has been entirely satisfactory.
U.S. Pat. No. 5,336,896, for example, shows an approach whereby the entire cellular phone, including the antenna, is placed in a shielding enclosure. The antenna is retracted and makes contact through the enclosure with a second antenna outside the enclosure. The second antenna is mounted on a tilt and swivel base so that it can be moved away from the user's head to reduce exposure to the radiation emanating from it. Even though the energy level may be reduced somewhat, the head of the user is still exposed directly to the radiation.